Directive transmission of energy



Oct. 1, 1929. GUNN 1,730,071

DIRECTIVE TRANSMISSION OF ENERGY Filed Dec. 15, 1924 WAVE B WAVE 7 TRAPTRAP 21 WAVL LENGTH WAVE LENGTH I900 METER$ I 9.97 METERS 1g. '2.

INVENTOR. R066 Cyan):

BY ATTORNEY.

Patented Oct. 1, 1929 ROSS GUNN, OF NEW HAVEN, CONNECTICUT DIRECTIVETRANSMISSION OF ENERGY Application filed December 15, 1924. Serial N'o.755,985.

This invention relates to wireless directive transmission systems, andthe primary object is the provision in a system of this kind of meansfor combining two directive radiating transmitters, transmitting atdifferent frequencies, so as to produce a directive beat. The intensityof this beat frequency is proportional to the product of the two radioamplitudes.

lVith the above and other more detailed objects in view, as will be setforth as the description of my invention proceeds, reference is made tothe attached drawing, in which Fig. 1 is a diagrammatic view of the twooscillating directive circuits, and

Fig. 2 is a diagram of the signal energy curve.

A number of various systems have been known for the directivetransmission of signals, as for example that set forth in Patent1,379,541, where signals are directively propagated from the source inpairs of quickly succeeding individual signals at small time intervals,the signal of each pair being in different directions, not only fromeach other but also from the corresponding individual signals of thepreceding pair of signals, and of the succeeding pair.

In the arrangement as will be set forth in my invention the ideainvolved depends on the fact that two oscillatory waves of differentradio frequencies will produce difference for beat frequencies, whichare proportional to the product of the two radio amplitudes whenproperly rectified at the receiver. This basic idea may be used with anystandard directive system, and in the example set forth in the figures,two loops 1 and 2 are shown connected to circuits 3 and 4 respectively.Circuit 3 is inductively coupled to a second circuit 5 which is adaptedto transmit or produce continuous waves of a wave length of 1000 meters.Circuit 4 is inductively coupled to a circuit 6, which is adapted toemit continuous waves of a wave length of for example 997 meters. A wavetrap 7 is inserted in circuit 3 so as to cut out frequencies generatedin circuit 6, and a second wave trap 8 is inserted in circuit 4 so as tocut out frequencies generated in circuit 3. A key 9 is included incircuit 6 so as to interrupt this circuit when so desired.

The two loops which form two directive radiating transmitters aremounted so as to be positioned about apart in azimuth.

If the two signals are sent out, that is, a signal of 997 meters ascontinuous waves in circuit 4 and signals of 1000 meters as continuouswaves in circuit 3, the effect of the relative positioning of the twoloops and the directional characteristics of these two loops will be ofdirective transmission of a beat note, which in the instance indicatedwould be at about 1000 cycles and hence audible in a telephone of alistener located at the point 10 of Figure 2. Since the beat note is ofan intensity proportional to the product of the two radio amplitudes,the beat note may be distinguishable for a great distance as compared toa signal generated in the customary manner, but will diminish to Zerointensity whenever the intensity of the signal from either directivetransmitter becomes zero. The key or interrupter 9 in circuit 6 isprovided so that one of the two radio signals may be stopped to cause adropping of the beat signal to zero, regardless of the intensity of theother radiated signal. The beats produced may be of an audiblefrequency, or they may be of sub or super audible, or of radiofrequency, and may be used as direct indicators or as carriers ofsignals, impulses or speech.

The signal energy curve for the example cited in the foregoing is shownin Fig. 2, and is in the shape of two elongated loops 11 and 12,extending radially 180 apart from a central point, and also the twosmall loops spaced 90 from the larger loops radiating from the centralpoint which is the point from which the signals are transmitted. Theenergy distribution curve therefore looks something like a four-leafclover instead of two circles as either loop alone would give.

An important case of the invention just set forth would be where thebeat frequency of the continuous waves is exactly equal to themodulation frequency superimposed on the main generated frequency.

I am aware that various modifications may be made of the beat examplewhich I have used for purposes of illustration of my invention.

I claim:

1. A Wireless directive transmission system the combination of aplurality of radiating directive transmitters adapted to radiatedirectionally in different directions, means for emitting continuousWaves from one directive transmitter at a definite frequency, means forsimultaneously emitting continuous Waves from the second directivetransmitter at a slightly different frequency, and means for modulatingone of said means.

2. A Wireless directive transmission system, comprising in combination,a plurality of radiating directive transmitters, means for emit-tingcontinuous Waves from one directive transmitter at a definite frequency,means for simultaneously emitting continuous Waves from the seconddirective transmitter at a slightly difi'erent frequency, and means formodulating one of said means so that the combined effect of said meansand said transmitters is to produce a radiated directional beat note ofaudio frequency, the beat frequency being equal to the modulationfrequency superposed on the main generator frequency. In testimonywhereof I afiix my signature.

ROSS GUNN.

